[media] cx23885: convert to vb2

As usual, this patch is very large due to the fact that half a vb2 conversion
isn't possible. And since this affects 417, alsa, core, dvb, vbi and video the
changes are all over.

What made this more difficult was the peculiar way the risc program was setup.
The driver allowed for running out of buffers in which case the DMA would stop
and restart when the next buffer was queued. There was also a complicated
timeout system for when buffers weren't filled. This was replaced by a much
simpler scheme where there is always one buffer around and the DMA will just
cycle that buffer until a new buffer is queued. In that case the previous
buffer will be chained to the new buffer. An interrupt is generated at the
start of the new buffer telling the driver that the previous buffer can be
passed on to userspace.

Much simpler and more robust. The old code seems to be copied from the
cx88 driver. But it didn't fit the vb2 ops very well and replacing it with
the new scheme made the code easier to understand. Not to mention that this
patch removes 600 lines of code.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 85 insertions, 220 deletions

diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c
index 0b6bbac6990f..8d77a5649777 100644
--- a/drivers/media/pci/cx23885/cx23885-core.c
+++ b/drivers/media/pci/cx23885/cx23885-core.c
@@ -416,39 +416,23 @@ static int cx23885_risc_decode(u32 risc)
 	return incr[risc >> 28] ? incr[risc >> 28] : 1;
 }
 
-void cx23885_wakeup(struct cx23885_tsport *port,
+static void cx23885_wakeup(struct cx23885_tsport *port,
 			   struct cx23885_dmaqueue *q, u32 count)
 {
 	struct cx23885_dev *dev = port->dev;
 	struct cx23885_buffer *buf;
-	int bc;
 
-	for (bc = 0;; bc++) {
-		if (list_empty(&q->active))
-			break;
-		buf = list_entry(q->active.next,
-				 struct cx23885_buffer, vb.queue);
-
-		/* count comes from the hw and is is 16bit wide --
-		 * this trick handles wrap-arounds correctly for
-		 * up to 32767 buffers in flight... */
-		if ((s16) (count - buf->count) < 0)
-			break;
-
-		v4l2_get_timestamp(&buf->vb.ts);
-		dprintk(2, "[%p/%d] wakeup reg=%d buf=%d\n", buf, buf->vb.i,
-			count, buf->count);
-		buf->vb.state = VIDEOBUF_DONE;
-		list_del(&buf->vb.queue);
-		wake_up(&buf->vb.done);
-	}
 	if (list_empty(&q->active))
-		del_timer(&q->timeout);
-	else
-		mod_timer(&q->timeout, jiffies + BUFFER_TIMEOUT);
-	if (bc != 1)
-		printk(KERN_WARNING "%s: %d buffers handled (should be 1)\n",
-		       __func__, bc);
+		return;
+	buf = list_entry(q->active.next,
+			 struct cx23885_buffer, queue);
+
+	v4l2_get_timestamp(&buf->vb.v4l2_buf.timestamp);
+	buf->vb.v4l2_buf.sequence = q->count++;
+	dprintk(1, "[%p/%d] wakeup reg=%d buf=%d\n", buf, buf->vb.v4l2_buf.index,
+		count, q->count);
+	list_del(&buf->queue);
+	vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
 }
 
 int cx23885_sram_channel_setup(struct cx23885_dev *dev,
@@ -478,8 +462,8 @@ int cx23885_sram_channel_setup(struct cx23885_dev *dev,
 		lines = 6;
 	BUG_ON(lines < 2);
 
-	cx_write(8 + 0, RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
-	cx_write(8 + 4, 8);
+	cx_write(8 + 0, RISC_JUMP | RISC_CNT_RESET);
+	cx_write(8 + 4, 12);
 	cx_write(8 + 8, 0);
 
 	/* write CDT */
@@ -695,10 +679,6 @@ static int get_resources(struct cx23885_dev *dev)
 	return -EBUSY;
 }
 
-static void cx23885_timeout(unsigned long data);
-int cx23885_risc_stopper(struct pci_dev *pci, struct btcx_riscmem *risc,
-				u32 reg, u32 mask, u32 value);
-
 static int cx23885_init_tsport(struct cx23885_dev *dev,
 	struct cx23885_tsport *port, int portno)
 {
@@ -715,11 +695,6 @@ static int cx23885_init_tsport(struct cx23885_dev *dev,
 	port->nr = portno;
 
 	INIT_LIST_HEAD(&port->mpegq.active);
-	INIT_LIST_HEAD(&port->mpegq.queued);
-	port->mpegq.timeout.function = cx23885_timeout;
-	port->mpegq.timeout.data = (unsigned long)port;
-	init_timer(&port->mpegq.timeout);
-
 	mutex_init(&port->frontends.lock);
 	INIT_LIST_HEAD(&port->frontends.felist);
 	port->frontends.active_fe_id = 0;
@@ -772,9 +747,6 @@ static int cx23885_init_tsport(struct cx23885_dev *dev,
 		BUG();
 	}
 
-	cx23885_risc_stopper(dev->pci, &port->mpegq.stopper,
-		     port->reg_dma_ctl, port->dma_ctl_val, 0x00);
-
 	return 0;
 }
 
@@ -1085,11 +1057,18 @@ static void cx23885_dev_unregister(struct cx23885_dev *dev)
 static __le32 *cx23885_risc_field(__le32 *rp, struct scatterlist *sglist,
 			       unsigned int offset, u32 sync_line,
 			       unsigned int bpl, unsigned int padding,
-			       unsigned int lines,  unsigned int lpi)
+			       unsigned int lines,  unsigned int lpi, bool jump)
 {
 	struct scatterlist *sg;
 	unsigned int line, todo, sol;
 
+
+	if (jump) {
+		*(rp++) = cpu_to_le32(RISC_JUMP);
+		*(rp++) = cpu_to_le32(0);
+		*(rp++) = cpu_to_le32(0); /* bits 63-32 */
+	}
+
 	/* sync instruction */
 	if (sync_line != NO_SYNC_LINE)
 		*(rp++) = cpu_to_le32(RISC_RESYNC | sync_line);
@@ -1164,7 +1143,7 @@ int cx23885_risc_buffer(struct pci_dev *pci, struct btcx_riscmem *risc,
 	/* write and jump need and extra dword */
 	instructions  = fields * (1 + ((bpl + padding) * lines)
 		/ PAGE_SIZE + lines);
-	instructions += 2;
+	instructions += 5;
 	rc = btcx_riscmem_alloc(pci, risc, instructions*12);
 	if (rc < 0)
 		return rc;
@@ -1173,10 +1152,10 @@ int cx23885_risc_buffer(struct pci_dev *pci, struct btcx_riscmem *risc,
 	rp = risc->cpu;
 	if (UNSET != top_offset)
 		rp = cx23885_risc_field(rp, sglist, top_offset, 0,
-					bpl, padding, lines, 0);
+					bpl, padding, lines, 0, true);
 	if (UNSET != bottom_offset)
 		rp = cx23885_risc_field(rp, sglist, bottom_offset, 0x200,
-					bpl, padding, lines, 0);
+					bpl, padding, lines, 0, UNSET == top_offset);
 
 	/* save pointer to jmp instruction address */
 	risc->jmp = rp;
@@ -1200,7 +1179,7 @@ int cx23885_risc_databuffer(struct pci_dev *pci,
 	   than PAGE_SIZE */
 	/* Jump and write need an extra dword */
 	instructions  = 1 + (bpl * lines) / PAGE_SIZE + lines;
-	instructions += 1;
+	instructions += 4;
 
 	rc = btcx_riscmem_alloc(pci, risc, instructions*12);
 	if (rc < 0)
@@ -1209,7 +1188,7 @@ int cx23885_risc_databuffer(struct pci_dev *pci,
 	/* write risc instructions */
 	rp = risc->cpu;
 	rp = cx23885_risc_field(rp, sglist, 0, NO_SYNC_LINE,
-				bpl, 0, lines, lpi);
+				bpl, 0, lines, lpi, lpi == 0);
 
 	/* save pointer to jmp instruction address */
 	risc->jmp = rp;
@@ -1239,7 +1218,7 @@ int cx23885_risc_vbibuffer(struct pci_dev *pci, struct btcx_riscmem *risc,
 	/* write and jump need and extra dword */
 	instructions  = fields * (1 + ((bpl + padding) * lines)
 		/ PAGE_SIZE + lines);
-	instructions += 2;
+	instructions += 5;
 	rc = btcx_riscmem_alloc(pci, risc, instructions*12);
 	if (rc < 0)
 		return rc;
@@ -1250,11 +1229,11 @@ int cx23885_risc_vbibuffer(struct pci_dev *pci, struct btcx_riscmem *risc,
 	 * in the userland vbi payload */
 	if (UNSET != top_offset)
 		rp = cx23885_risc_field(rp, sglist, top_offset, 6,
-					bpl, padding, lines, 0);
+					bpl, padding, lines, 0, true);
 
 	if (UNSET != bottom_offset)
 		rp = cx23885_risc_field(rp, sglist, bottom_offset, 0x207,
-					bpl, padding, lines, 0);
+					bpl, padding, lines, 0, UNSET == top_offset);
 
 
 
@@ -1265,38 +1244,10 @@ int cx23885_risc_vbibuffer(struct pci_dev *pci, struct btcx_riscmem *risc,
 }
 
 
-int cx23885_risc_stopper(struct pci_dev *pci, struct btcx_riscmem *risc,
-				u32 reg, u32 mask, u32 value)
-{
-	__le32 *rp;
-	int rc;
-
-	rc = btcx_riscmem_alloc(pci, risc, 4*16);
-	if (rc < 0)
-		return rc;
-
-	/* write risc instructions */
-	rp = risc->cpu;
-	*(rp++) = cpu_to_le32(RISC_WRITECR  | RISC_IRQ2);
-	*(rp++) = cpu_to_le32(reg);
-	*(rp++) = cpu_to_le32(value);
-	*(rp++) = cpu_to_le32(mask);
-	*(rp++) = cpu_to_le32(RISC_JUMP);
-	*(rp++) = cpu_to_le32(risc->dma);
-	*(rp++) = cpu_to_le32(0); /* bits 63-32 */
-	return 0;
-}
-
-void cx23885_free_buffer(struct videobuf_queue *q, struct cx23885_buffer *buf)
+void cx23885_free_buffer(struct cx23885_dev *dev, struct cx23885_buffer *buf)
 {
-	struct videobuf_dmabuf *dma = videobuf_to_dma(&buf->vb);
-
 	BUG_ON(in_interrupt());
-	videobuf_waiton(q, &buf->vb, 0, 0);
-	videobuf_dma_unmap(q->dev, dma);
-	videobuf_dma_free(dma);
-	btcx_riscmem_free(to_pci_dev(q->dev), &buf->risc);
-	buf->vb.state = VIDEOBUF_NEEDS_INIT;
+	btcx_riscmem_free(dev->pci, &buf->risc);
 }
 
 static void cx23885_tsport_reg_dump(struct cx23885_tsport *port)
@@ -1351,7 +1302,7 @@ static void cx23885_tsport_reg_dump(struct cx23885_tsport *port)
 		port->reg_ts_int_msk, cx_read(port->reg_ts_int_msk));
 }
 
-static int cx23885_start_dma(struct cx23885_tsport *port,
+int cx23885_start_dma(struct cx23885_tsport *port,
 			     struct cx23885_dmaqueue *q,
 			     struct cx23885_buffer   *buf)
 {
@@ -1359,7 +1310,7 @@ static int cx23885_start_dma(struct cx23885_tsport *port,
 	u32 reg;
 
 	dprintk(1, "%s() w: %d, h: %d, f: %d\n", __func__,
-		buf->vb.width, buf->vb.height, buf->vb.field);
+		dev->width, dev->height, dev->field);
 
 	/* Stop the fifo and risc engine for this port */
 	cx_clear(port->reg_dma_ctl, port->dma_ctl_val);
@@ -1375,7 +1326,7 @@ static int cx23885_start_dma(struct cx23885_tsport *port,
 	}
 
 	/* write TS length to chip */
-	cx_write(port->reg_lngth, buf->vb.width);
+	cx_write(port->reg_lngth, port->ts_packet_size);
 
 	if ((!(cx23885_boards[dev->board].portb & CX23885_MPEG_DVB)) &&
 		(!(cx23885_boards[dev->board].portc & CX23885_MPEG_DVB))) {
@@ -1404,7 +1355,7 @@ static int cx23885_start_dma(struct cx23885_tsport *port,
 	/* NOTE: this is 2 (reserved) for portb, does it matter? */
 	/* reset counter to zero */
 	cx_write(port->reg_gpcnt_ctl, 3);
-	q->count = 1;
+	q->count = 0;
 
 	/* Set VIDB pins to input */
 	if (cx23885_boards[dev->board].portb == CX23885_MPEG_DVB) {
@@ -1493,134 +1444,83 @@ static int cx23885_stop_dma(struct cx23885_tsport *port)
 	return 0;
 }
 
-int cx23885_restart_queue(struct cx23885_tsport *port,
-				struct cx23885_dmaqueue *q)
-{
-	struct cx23885_dev *dev = port->dev;
-	struct cx23885_buffer *buf;
-
-	dprintk(5, "%s()\n", __func__);
-	if (list_empty(&q->active)) {
-		struct cx23885_buffer *prev;
-		prev = NULL;
-
-		dprintk(5, "%s() queue is empty\n", __func__);
-
-		for (;;) {
-			if (list_empty(&q->queued))
-				return 0;
-			buf = list_entry(q->queued.next, struct cx23885_buffer,
-					 vb.queue);
-			if (NULL == prev) {
-				list_move_tail(&buf->vb.queue, &q->active);
-				cx23885_start_dma(port, q, buf);
-				buf->vb.state = VIDEOBUF_ACTIVE;
-				buf->count    = q->count++;
-				mod_timer(&q->timeout, jiffies+BUFFER_TIMEOUT);
-				dprintk(5, "[%p/%d] restart_queue - f/active\n",
-					buf, buf->vb.i);
-
-			} else if (prev->vb.width  == buf->vb.width  &&
-				   prev->vb.height == buf->vb.height &&
-				   prev->fmt       == buf->fmt) {
-				list_move_tail(&buf->vb.queue, &q->active);
-				buf->vb.state = VIDEOBUF_ACTIVE;
-				buf->count    = q->count++;
-				prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
-				/* 64 bit bits 63-32 */
-				prev->risc.jmp[2] = cpu_to_le32(0);
-				dprintk(5, "[%p/%d] restart_queue - m/active\n",
-					buf, buf->vb.i);
-			} else {
-				return 0;
-			}
-			prev = buf;
-		}
-		return 0;
-	}
-
-	buf = list_entry(q->active.next, struct cx23885_buffer, vb.queue);
-	dprintk(2, "restart_queue [%p/%d]: restart dma\n",
-		buf, buf->vb.i);
-	cx23885_start_dma(port, q, buf);
-	list_for_each_entry(buf, &q->active, vb.queue)
-		buf->count = q->count++;
-	mod_timer(&q->timeout, jiffies + BUFFER_TIMEOUT);
-	return 0;
-}
-
 /* ------------------------------------------------------------------ */
 
-int cx23885_buf_prepare(struct videobuf_queue *q, struct cx23885_tsport *port,
-			struct cx23885_buffer *buf, enum v4l2_field field)
+int cx23885_buf_prepare(struct cx23885_buffer *buf, struct cx23885_tsport *port)
 {
 	struct cx23885_dev *dev = port->dev;
 	int size = port->ts_packet_size * port->ts_packet_count;
+	struct sg_table *sgt = vb2_dma_sg_plane_desc(&buf->vb, 0);
 	int rc;
 
 	dprintk(1, "%s: %p\n", __func__, buf);
-	if (0 != buf->vb.baddr  &&  buf->vb.bsize < size)
+	if (vb2_plane_size(&buf->vb, 0) < size)
 		return -EINVAL;
+	vb2_set_plane_payload(&buf->vb, 0, size);
 
-	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
-		buf->vb.width  = port->ts_packet_size;
-		buf->vb.height = port->ts_packet_count;
-		buf->vb.size   = size;
-		buf->vb.field  = field /*V4L2_FIELD_TOP*/;
-
-		rc = videobuf_iolock(q, &buf->vb, NULL);
-		if (0 != rc)
-			goto fail;
-		cx23885_risc_databuffer(dev->pci, &buf->risc,
-					videobuf_to_dma(&buf->vb)->sglist,
-					buf->vb.width, buf->vb.height, 0);
-	}
-	buf->vb.state = VIDEOBUF_PREPARED;
-	return 0;
+	rc = dma_map_sg(&dev->pci->dev, sgt->sgl, sgt->nents, DMA_FROM_DEVICE);
+	if (!rc)
+		return -EIO;
 
- fail:
-	cx23885_free_buffer(q, buf);
-	return rc;
+	cx23885_risc_databuffer(dev->pci, &buf->risc,
+				sgt->sgl,
+				port->ts_packet_size, port->ts_packet_count, 0);
+	return 0;
 }
 
+/*
+ * The risc program for each buffer works as follows: it starts with a simple
+ * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
+ * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
+ * the initial JUMP).
+ *
+ * This is the risc program of the first buffer to be queued if the active list
+ * is empty and it just keeps DMAing this buffer without generating any
+ * interrupts.
+ *
+ * If a new buffer is added then the initial JUMP in the code for that buffer
+ * will generate an interrupt which signals that the previous buffer has been
+ * DMAed successfully and that it can be returned to userspace.
+ *
+ * It also sets the final jump of the previous buffer to the start of the new
+ * buffer, thus chaining the new buffer into the DMA chain. This is a single
+ * atomic u32 write, so there is no race condition.
+ *
+ * The end-result of all this that you only get an interrupt when a buffer
+ * is ready, so the control flow is very easy.
+ */
 void cx23885_buf_queue(struct cx23885_tsport *port, struct cx23885_buffer *buf)
 {
 	struct cx23885_buffer    *prev;
 	struct cx23885_dev *dev = port->dev;
 	struct cx23885_dmaqueue  *cx88q = &port->mpegq;
+	unsigned long flags;
 
-	/* add jump to stopper */
-	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
-	buf->risc.jmp[1] = cpu_to_le32(cx88q->stopper.dma);
+	buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
+	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
+	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
 	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
 
+	spin_lock_irqsave(&dev->slock, flags);
 	if (list_empty(&cx88q->active)) {
-		dprintk(1, "queue is empty - first active\n");
-		list_add_tail(&buf->vb.queue, &cx88q->active);
-		cx23885_start_dma(port, cx88q, buf);
-		buf->vb.state = VIDEOBUF_ACTIVE;
-		buf->count    = cx88q->count++;
-		mod_timer(&cx88q->timeout, jiffies + BUFFER_TIMEOUT);
+		list_add_tail(&buf->queue, &cx88q->active);
 		dprintk(1, "[%p/%d] %s - first active\n",
-			buf, buf->vb.i, __func__);
+			buf, buf->vb.v4l2_buf.index, __func__);
 	} else {
-		dprintk(1, "queue is not empty - append to active\n");
+		buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
 		prev = list_entry(cx88q->active.prev, struct cx23885_buffer,
-				  vb.queue);
-		list_add_tail(&buf->vb.queue, &cx88q->active);
-		buf->vb.state = VIDEOBUF_ACTIVE;
-		buf->count    = cx88q->count++;
+				  queue);
+		list_add_tail(&buf->queue, &cx88q->active);
 		prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
-		prev->risc.jmp[2] = cpu_to_le32(0); /* 64 bit bits 63-32 */
 		dprintk(1, "[%p/%d] %s - append to active\n",
-			 buf, buf->vb.i, __func__);
+			 buf, buf->vb.v4l2_buf.index, __func__);
 	}
+	spin_unlock_irqrestore(&dev->slock, flags);
 }
 
 /* ----------------------------------------------------------- */
 
-static void do_cancel_buffers(struct cx23885_tsport *port, char *reason,
-			      int restart)
+static void do_cancel_buffers(struct cx23885_tsport *port, char *reason)
 {
 	struct cx23885_dev *dev = port->dev;
 	struct cx23885_dmaqueue *q = &port->mpegq;
@@ -1630,16 +1530,11 @@ static void do_cancel_buffers(struct cx23885_tsport *port, char *reason,
 	spin_lock_irqsave(&port->slock, flags);
 	while (!list_empty(&q->active)) {
 		buf = list_entry(q->active.next, struct cx23885_buffer,
-				 vb.queue);
-		list_del(&buf->vb.queue);
-		buf->vb.state = VIDEOBUF_ERROR;
-		wake_up(&buf->vb.done);
+				 queue);
+		list_del(&buf->queue);
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
 		dprintk(1, "[%p/%d] %s - dma=0x%08lx\n",
-			buf, buf->vb.i, reason, (unsigned long)buf->risc.dma);
-	}
-	if (restart) {
-		dprintk(1, "restarting queue\n");
-		cx23885_restart_queue(port, q);
+			buf, buf->vb.v4l2_buf.index, reason, (unsigned long)buf->risc.dma);
 	}
 	spin_unlock_irqrestore(&port->slock, flags);
 }
@@ -1647,27 +1542,10 @@ static void do_cancel_buffers(struct cx23885_tsport *port, char *reason,
 void cx23885_cancel_buffers(struct cx23885_tsport *port)
 {
 	struct cx23885_dev *dev = port->dev;
-	struct cx23885_dmaqueue *q = &port->mpegq;
-
-	dprintk(1, "%s()\n", __func__);
-	del_timer_sync(&q->timeout);
-	cx23885_stop_dma(port);
-	do_cancel_buffers(port, "cancel", 0);
-}
-
-static void cx23885_timeout(unsigned long data)
-{
-	struct cx23885_tsport *port = (struct cx23885_tsport *)data;
-	struct cx23885_dev *dev = port->dev;
 
 	dprintk(1, "%s()\n", __func__);
-
-	if (debug > 5)
-		cx23885_sram_channel_dump(dev,
-			&dev->sram_channels[port->sram_chno]);
-
 	cx23885_stop_dma(port);
-	do_cancel_buffers(port, "timeout", 1);
+	do_cancel_buffers(port, "cancel");
 }
 
 int cx23885_irq_417(struct cx23885_dev *dev, u32 status)
@@ -1717,11 +1595,6 @@ int cx23885_irq_417(struct cx23885_dev *dev, u32 status)
 		spin_lock(&port->slock);
 		cx23885_wakeup(port, &port->mpegq, count);
 		spin_unlock(&port->slock);
-	} else if (status & VID_B_MSK_RISCI2) {
-		dprintk(7, "        VID_B_MSK_RISCI2\n");
-		spin_lock(&port->slock);
-		cx23885_restart_queue(port, &port->mpegq);
-		spin_unlock(&port->slock);
 	}
 	if (status) {
 		cx_write(port->reg_ts_int_stat, status);
@@ -1773,14 +1646,6 @@ static int cx23885_irq_ts(struct cx23885_tsport *port, u32 status)
 		cx23885_wakeup(port, &port->mpegq, count);
 		spin_unlock(&port->slock);
 
-	} else if (status & VID_BC_MSK_RISCI2) {
-
-		dprintk(7, " (RISCI2            0x%08x)\n", VID_BC_MSK_RISCI2);
-
-		spin_lock(&port->slock);
-		cx23885_restart_queue(port, &port->mpegq);
-		spin_unlock(&port->slock);
-
 	}
 	if (status) {
 		cx_write(port->reg_ts_int_stat, status);